Granular magnesium salts

Abstract

Granules of magnesium salts are obtained by spraying onto agitated feed particles of the salt a small amount of a dilute aqueous solution of a synthetic poly hydroxy-substituted compound, such as polyvinylalcohol, and drying the resultant agglomerate. It is especially suitable to carry out the granulation process in a warm air fluidized bed using feed particles of mainly below 200 microns producing eventually a low bulk density product mainly in the range 200-100 microns. The granular salts have a particle size of from 0.15 to 1.0 mm and a free-flowing bulk density of from 0.3 to 0.6 kg/l.

We claim: 
     
       1. Granular magnesium monoperoxyphthalate, having a particle size of from 0.15 to 1.0 mm. being attrition resistant, having a free-flowing bulk density of from 0.3 to 0.6 kg/l, and having a solubility in water of at least 70% by weight, said solubility being calculated by comparing dissolved available oxygen with the known available oxygen of the granular material, said dissolved oxygen content being determined by stirring 0.25 grams of the granular salt in 25 ml. of water at 20° C. in a centrifuge tube for 15 seconds, centrifuging for 30 seconds, decanting the supernatant liquid, and determining the available oxygen content of the supernatant liquid. 
     
     
       2. A granular magnesium salt according to claim 1 wherein said granular salt comprises agglomerated particles having a geometric mean diameter of 75-100 microns. 
     
     
       3. A granular magnesium salt according to claim 1 further comprising an agglomerating agent, said agglomerating agent comprising a hydroxylated organic polymer. 
     
     
       4. A granular magnesium salt according to claim 3 wherein said hydroxylated organic polymer comprises polyvinyl alochol.